AudioLens: Multi-Perspective Speech Clustering with Reasoning Audio-Language Models
Organizations: University of California, Irvine · Independent Researcher · Dartmouth College · Purdue University Northwest
Abstract
Audio clustering is a fundamental task for organizing rapidly growing speech collections, supporting applications such as conversational analysis and speech-driven discovery. However, existing methods rely on fixed acoustic similarity metrics or ASR-based text pipelines, limiting their ability to reorganize the same audio collection under different user-specified perspectives, especially when clustering depends on both linguistic and paralinguistic cues. We introduce audio multi-perspective clustering, where a model directly partitions speech recordings according to a natural-language perspective while inferring both the number of clusters and their assignments. To study this setting, we construct AudioLens-Bench, a benchmark spanning multiple application domains and evaluating both in-perspective and cross-perspective generalization. We further propose AudioLens-R1, an end-to-end large audio-language model trained with reasoning distillation and preference optimization. Experiments show that AudioLens-R1 consistently outperforms all baselines, improving overall ARI by 12.99 points and V-measure by 11.62 points. These results demonstrate the promise of native audio-language models for flexible, perspective-conditioned structure discovery over speech collections.
Figures & tables
| Dataset | Train | |||||||
|---|---|---|---|---|---|---|---|---|
| #Audio | #Data | #Audio | #Data | #Audio | #Data | #Audio | #Data | |
| Banking77 | 641 | 4110 | 584 | 1863 | 519 | 1800 | 599 | 1849 |
| MultiWOZ | 466 | 1571 | 479 | 1617 | 440 | 1574 | 499 | 1578 |
| ECHR | 519 | 3795 | 478 | 1735 | 453 | 1665 | 478 | 1670 |
| S&P 500 | 472 | 3907 | 404 | 1784 | 373 | 1700 | 396 | 1689 |
| Method | Clustering | ECHR | S&P 500 | Banking77 | MultiWOZ | Average | Overall | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASR (Whisper Radford et al. (2023) ) + Text Embedding + Clustering | |||||||||||||||||
| K-Means | 4.98 | 4.24 | 8.82 | 9.90 | 5.71 | 5.42 | 8.29 | 6.83 | 6.83 | 4.73 | 4.77 | 8.81 | 6.97 | 5.39 | 7.47 | 6.61 | |
| InBedder Peng et al. (2024) | GMM | 1.58 | 2.56 | 9.06 | 2.89 | 2.15 | 3.73 | 5.20 | 8.11 | 9.57 | 5.43 | 3.92 | 7.16 | 3.77 | 4.18 | 7.38 | 5.11 |
| K-Means | 12.18 | 15.40 | 26.51 | 16.19 | 18.79 | 15.56 | 23.57 | 24.68 | 18.18 | 10.55 | 11.41 | 11.09 | 15.62 | 17.57 | 17.84 | 17.01 | |
| Instructor Su et al. (2023) | GMM | 8.44 | 9.68 | 17.30 | 9.37 | 9.46 | 6.98 | 14.79 | 13.13 | 14.65 | 7.30 | 7.66 | 6.48 | 9.97 | 9.98 | 11.35 | 10.44 |
| Method | Clustering | ECHR | S&P 500 | Banking77 | MultiWOZ | Average | Overall | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASR (Whisper Radford et al. (2023) ) + Text Embedding + Clustering | |||||||||||||||||
| K-Means | 50.71 | 51.51 | 57.84 | 53.69 | 50.88 | 48.79 | 52.13 | 52.87 | 50.09 | 30.24 | 29.38 | 29.55 | 46.69 | 46.16 | 46.57 | 46.47 | |
| InBedder Peng et al. (2024) | GMM | 49.19 | 50.79 | 58.20 | 50.64 | 49.54 | 48.81 | 50.71 | 54.13 | 53.02 | 31.49 | 29.43 | 28.97 | 45.51 | 45.97 | 47.25 | 46.24 |
| Instructor Su et al. (2023) | K-Means | 55.50 | 57.76 | 67.36 | 57.81 | 59.13 | 54.67 | 60.18 | 61.91 | 57.21 | 34.75 | 34.41 | 31.18 | 52.06 | 53.30 | 52.61 | 52.66 |
| GMM | 53.50 | 55.07 | 62.85 | 54.41 | 53.58 | 50.40 | 56.26 | 57.21 | 55.96 | 32.98 | 32.15 | 28.51 | 49.29 | 49.50 | 49.43 | 49.41 | |
| Metric | Corpus / Split | Answer-only SFT | RD SFT | Answer-only + DPO | RD + DPO |
|---|---|---|---|---|---|
| ARI | ECHR | 33.17 | 33.85 | 35.38 | 42.02 |
| S&P 500 | 33.30 | 38.23 | 37.58 | 42.73 | |
| Banking77 | 39.50 | 39.48 | 41.26 | 49.85 | |
| MultiWOZ | 33.34 | 32.34 | 34.07 | 44.50 | |
| Overall | 34.83 | 35.97 | 37.07 | 44.77 | |
| – |
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
| Corpus | Transcript Generation | Validation | TTS Path |
|---|---|---|---|
| Banking77 | Classify each short intent query under the refined taxonomy, then expand each classifiable query into a natural spoken transcript (monologue or short dialogue). | Re-classify the expanded transcript under the same taxonomy and retain it only if all transcript-level labels exactly match the original query-level assignments. | Synthesize validated transcripts with sampled emotion and speaker identity; use one speaker for monologues and multiple speakers for dialogues; augment the waveform with background-noise conditions. |
| ECHR | Assign taxonomy labels to long legal case texts, compress each accepted case into an evidence-preserving summary, and rewrite the summary into a spoken script. | Use dual-model agreement for source-text labeling, then re-classify the compressed text and retain it only if all previously accepted dimensions remain recoverable after compression. | Synthesize accepted spoken scripts with one to four speakers, sampled emotion, and background-noise conditions, with approximate balancing of paralinguistic factors within semantic strata. |
| S&P 500 | Assign taxonomy labels to 10-K disclosure segments, compress each accepted document into an evidence-preserving summary, and rewrite the summary into a spoken script. | Use dual-model agreement for source-text labeling, then re-classify the compressed text and retain it only if all accepted dimensions are preserved after compression. | Synthesize accepted spoken scripts with sampled emotion, speaker count, and background-noise condition, again using a balanced assignment scheme within semantic strata. |
| MultiWOZ | Directly reuse sampled human-written dialogues as transcripts after assigning taxonomy labels. | Retain only dialogues for which two independent classifiers produce identical label assignments across all taxonomy dimensions. | Synthesize the validated dialogue turn by turn with distinct speakers for different roles, while injecting sampled emotion and background-noise variation. |
| Corpus | Held-in perspectives | Held-out perspectives |
|---|---|---|
| Banking77 | • Cluster requests by the customer’s primary intended outcome • Cluster requests by the main banking problem or request category • Cluster requests by the dominant urgency, severity, or risk level • Cluster clips by the dominant emotional tone in speech • Cluster clips by the exact number of distinct speakers • Cluster clips by the real-world background-noise scene | • Cluster requests by the banking capability or product domain most directly involved • Cluster requests by the primary route through which the issue would be resolved • Cluster clips by the dominant speaker-gender pattern |
| ECHR | • Cluster cases by the dominant State act or omission producing the alleged violation • Cluster cases by the procedural or situational context of the dispute • Cluster cases by the structure of the dispute and party configuration • Cluster clips by the dominant emotional tone in speech • Cluster clips by the exact number of distinct speakers • Cluster clips by the real-world background-noise scene | • Cluster cases by the principal protected interest implicated • Cluster cases by the main kind of harm or outcome alleged • Cluster cases by the most salient applicant status affecting power imbalance or risk • Cluster clips by the dominant speaker-gender pattern |
| S&P 500 | • Cluster firms by the primary way key properties are controlled • Cluster firms by the geographic breadth and concentration of properties • Cluster firms by the dominant type of legal matter discussed • Cluster firms by the dominant signal about legal-matter status and potential financial impact • Cluster clips by the dominant emotional tone in speech • Cluster clips by the exact number of distinct speakers • Cluster clips by the real-world background-noise scene | • Cluster disclosures by the dominant type of physical properties central to operations • Cluster disclosures by the dominant approach to shareholder return • Cluster disclosures by the dominant approach to repurchases or equity structure • Cluster clips by the dominant speaker-gender pattern |
| MultiWOZ | • Cluster dialogues by the presence and source of explicit repair turns • Cluster dialogues by how users provide, accumulate, revise, or confirm constraints • Cluster dialogues by the balance between information-seeking and transaction-execution content • Cluster dialogues by whether the task succeeds directly, partially succeeds, fails, or is recovered through fallback • Cluster clips by the dominant emotional tone in speech • Cluster clips by the exact number of distinct speakers • Cluster clips by the real-world background-noise scene | • Cluster dialogues by how much earlier information must be remembered and reused later • Cluster dialogues by who drives the interaction and how strongly negotiation shapes the exchange • Cluster dialogues by whether the interaction stays within a narrow goal or couples multiple domains or subgoals • Cluster clips by the dominant speaker-gender pattern |
| Source | Episodes | Unique audios | Clips / episode | Gold | Duration (s) |
|---|---|---|---|---|---|
| All SFT train | 1,876 | 2,008 | 5.64 (7, 10) | 3.37 (6, 9) | 373.5 (524.6, 539.9) |
| ECHR | 539 | 501 | 5.51 (7, 7) | 3.37 (6, 7) | 452.8 (531.4, 539.9) |
| S&P 500 | 571 | 455 | 5.69 (7, 9) | 3.45 (6, 9) | 411.4 (525.2, 539.2) |
| Banking77 | 523 | 618 | 5.88 (8, 10) | 3.66 (7, 9) | 306.3 (431.1, 538.1) |
| MultiWOZ | 243 | 434 | 5.33 (7, 7) | 2.56 (4, 5) | 253.0 (372.3, 445.3) |
| Metric | Training | ECHR | S&P 500 | Banking77 | MultiWOZ | Overall | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BG | Emo. | Spk. | Gen. | Reason | BG | Emo. | Spk. | Gen. | Reason | BG | Emo. | Spk. | Gen. | Reason | BG | Emo. | Spk. | Gen. | Reason | BG | Emo. | Spk. | Gen. | Reason | ||
| ARI | RD SFT | 0.2947 | 0.2809 | 0.2682 | 0.2806 | 0.3872 | 0.3754 | 0.3096 | 0.3212 | 0.3539 | 0.3968 | 0.3380 | 0.2616 | 0.3025 | 0.3803 | 0.4749 | 0.3127 | 0.3664 | 0.0000 | 0.3823 | 0.4067 | 0.3302 | 0.3046 | 0.2230 | 0.3493 | 0.4164 |
| RD+DPO | 0.3163 | 0.2882 | 0.2727 | 0.2993 | 0.3821 | 0.3965 | 0.3169 | 0.3293 | 0.3554 | 0.4014 | 0.3818 | 0.2437 | 0.3448 | 0.3786 | 0.4507 | 0.3407 | 0.3557 | 0.0000 | 0.3724 | 0.4010 | 0.3588 | 0.3012 | 0.2367 | 0.3514 | 0.4088 | |
| V-measure | RD SFT | 0.6135 | 0.6772 | 0.6212 | 0.5756 | 0.8025 | 0.6460 | 0.6879 | 0.6294 | 0.5866 | 0.7717 | 0.5475 | 0.6769 | 0.4725 | 0.5801 | 0.8592 | 0.5115 | 0.7023 | 0.0000 | 0.5134 | 0.6240 | 0.5796 | 0.6861 | 0.4308 | 0.5639 | 0.7643 |
| RD+DPO | 0.6221 | 0.6827 | 0.6223 | 0.5864 | 0.8000 | 0.6595 | 0.6920 | 0.6329 | 0.5837 | 0.7689 | 0.5834 | 0.6660 | 0.4921 | 0.5779 | 0.8485 | 0.5384 | 0.6985 | 0.0000 | 0.5141 | 0.6238 | 0.6008 | 0.6848 | 0.4368 | 0.5655 | 0.7603 | |
Audio-Language Models
Audio-language models connect audio and natural language for understanding, retrieval, dialogue, speech generation, and music or sound analysis.
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